Grinding and polishing machine



c. DELAFONTAINE ETAL 2,454,597 GRINDING AND POLISHING MACHINE Nov. 23, 194s.;

Filed Aug.v 22, 1945 i A//\/ VLM/70H5. MM2/M M/Zz:

A BYv WMS that the stationary cesses shaped to fit and hold the diamond being processed. These holding members are readily interchangeable for others of different shapes. They may be separated from engagement with the diamond by turning the screw 53 so that the stud 52 is released, and clamped in holding position by turning down the screw 53.

It will be noted that the opening between the 'branches 30 and 43 in'lthe head 29 facing the lapping wheel I6 is unsymmetrical in its shape,

.Y that is to say, the branch 30 is offset substantially bearings 23 are fully exposed and the spindle unit may be conveniently removed or replaced therein and then clamped in operative position.

The spindle unit comprises ya hollow shaft 21"' rotating in a pair of bushings 2| that i'lt the bearings 23-24, carrying at its right hand end a pinion 28 and at its left'hand end a head 29 more than the branch 43. This arrangement provides ample space for the worm and worm wheel drive to the shaft 4| and the geared con- .nection between'the shaft 4| and the holding cup 45. It will be understood that it is necessary to drive only one of these cups, in this case the cup 45, and that the cooperating cup 5| will be rotated having transversely extending branches or forks offset substantially with the shaft. l I y The pinion 28 is arranged'to mesh with an intermediate gear 3|v journaled on a stud projecting from the rear portionof the standard 22. That gear in turn meshes with a similar gear 32 located immediately beneath it, and the gear 32 meshes with a driving pinion 33' fast on a horizontal shaft 34 whichv is journaled in the standard 22. The shaft 34 carries a driving pulley 35'by respect to the axis of which it may be driven from any suitable source.,

of power.

The shaft 34 carries also a large driving pinion 36 which meshes directly with a pinion 31 `fast upon the outer end of a solid shaft 38 which is rotatably and concentrically disposed within the.v

hollow shaft 21. By the gear mechanism above described it will be seen that the shafts 21 and l 38 are driven in the same directions, with the shaft 38 travelling at a somewhat faster rate of revolution.

At its extreme 4left hand end the solid shaft 38 Y carries a worm 39, and this in turn meshes with a worm wheel 48 fast to a short shaft 4| journaled in the branches of the head 28. The shaft 4| is shown in horizontal position in Fig. 1 and Y in vertical position in Figs. 2 and 4. The shaft 4| is provided at its lower end, as shown in Figs. 2 and 4, with a pinion 42 for rotating the diamond holding members or cups. The lower branch 3|) and the upper branch 43 of the head 29 are provided with aligned bearings which are parallel to the bearings of the shaft 4|. In one of these bearings, i. e., that shown in Fig. 4 as in the lower branch, is journaled the stem 44 of a diamond holding cup or member 45. Formed integral with this is a pinion 46 which meshes with the pinion 42 on the shaft 4|. In the lower end of the journal for the stem 44 is provided a removable plug or stud 41. An anti-friction support is provided for the stem 44 by securing a hardened ball `48 to the lower end of the stem 44 and a similar ball to the upper end of the stud 41. The stud 41 is v removably retained in the bore of the bearing by a collar screw 49 which Ais threaded into the face of the lower branch 38 and overlaps the en dof the stud 41.

.In the upper branch 43 of the head is journaled the stem 58 of a diamond holding cup or member 5|. The stem 58 is supported upon ball thrust bearings by a stud 52 and that in turn is adjustably retained in place by a knurled screw 53 threaded into the upper face of the Vbranch 43 ofthe head 29 and overlapping the end of the stud. Both the cup members 45 and 5| are provided in their opposed ends with conical r`e.

with the interposed diamond. diamond properly between the by its'en'gagement Having placed a Icups-45 and 5| and moved the lapping wheel standard I toward the right to a position corresponding to the desired lapping pressure, the maple.

`Chine may be set in operation by driving the lapping wheel at a speed of 1600 R. P. M. and the driven shaft 34 at a rate of 16 R. P. M., for exam- Under these conditions the head 29 may *be rotated at approximately 18 R. P. M. and the holding cups at approximately 1 revolution in about 28 minutes. The result is that the dial mond is rotated against the lapping wheel about itsl own longitudinal axis at the slower rate and is simultaneously moved bodily in a circular path in which the cutting or grinding angle of the area of Contact is continually being changed. The result of these two movements is to produce a ksmooth polished girdle in the diamond.

It will be understood, of course, that the speeds above 'suggested are illustrative only and may be widely Varied in accordance with the requirements of the work in hand. It will be noted that the effective rotation of the worm 39 is a differential. Both the shaft 21 and the shaft 38 rotate in the same direction and accordingly it is only the number of revolutions made by the shaft 38y in excess of the the number of revolutions made by the hollow shaft 21 that are ef- VHfective to vdrive the worm Wheel 40. For example, pinions 36 yand 31 may both have sixtyfour teeth, and the intermediate gears 33 and 28 may have forty and forty-one teeth or vice versa.

-In that case the gear 28 and the shaft 21 will y gain one tooth in each revolution over the gear 33 and the shaft 38.

In Fig. 3 is shown an alternative connection to the shaft 38 by the use of which the rotation of the diamond about its own axis is made intermittent instead of continuous, and the surface of l the girdle is formed as flat facets instead of being smooth. When it is desired to operate the machine in this manner a pinion 31 `which is loose on the shaft 38 is substituted for the pin-A fion 31 of Fig. l, the intermediate gears 3| and 32 remain-in mesh and a forty tooth pinion is i substituted for the forty-one tooth pinion so that there is no differential movement between the two shafts and no rotation of the diamond .,whilea facet is being cut thereon. The gear 31' is provided with a series of equally spaced holes 60, for example four, and with these cooperates a locking pin 6| mounted in an arm fast to the end of the inner shaft 38. The locking pin 6| serves tohold the pinion 31 and the shaft 38 in fixed relation for an interval of the lapping operation sufcient to form a flat facet. ,n Meanwhile, of course, the rotary movement of the head 29 is carried out as before described. When one facet has been completed, the locking pin 6I is withdrawn and the gear 31 indexed to the next hole. When the gear 31 is provided with four holes, one quarter turn of the gear will correspond to 9 rotation of the diamond, giving forty facets in complete circumference.

When the indexing head is used, gears of an equal number of teeth are employed between the hollow shaft 21 and the driven shaft 34, and between the solid shaft 38 and the driven shaft 3d. The result is that both shafts turn at the same rate and there is no effective rotation of the worm 39. 1n this indexing operation the only effective rotation of the worm is caused by moving the arm 62 from one hole to another, and this may be carried out either by hand or rnechanically.

Having thus disclosed our invention and described in detail a preferred embodiment thereof, we claim as new and desire to secure by Letters Patent:

1. A diamond poli-shing machine for forming a continuous circumferential girdle about a diamend, including in its structure a lapping wheel rotatable about a fixed axis and spring means for holding the wheel in operative position, in combination with a pair of telescopically arranged shafts rotatable about an axis parallel to but eccentric with respect to the axis of the lapping wheel, a diamond holder carried by the said shafts and rotatable about an axis at right angles to that of the lapping wheel and also rotatable about a fixed axis eccentric with respect to that of said wheel, and a single common means for driving the holder about both of said axes.

2. In a diamond polishing machine having a lapping wheel rotatable about a predetermined axis, a diamond holder comprising a pair of telescopic shafts rotatable about an axis parallel and eccentric with respect to the axis of said wheel, a head carried by and rotatable with one of said shafts, diamond clamping cups journaled in the head to rotate about an axis at right angles to that of the telescopic shafts, and a driving train between the other of said shafts and said cups.

3. In a polishing machine or the like having a lapping wheel rotatable about a predetermined axis, mechanism for presenting a diamond to the wheel comprising a pair of concentric shafts, means for supporting and driving the shafts in the same directions about a common axis eccentric with respect to that of the wheel, a forked head carried by the outer shaft, holding cups journaled in the outer end of the head to rotate about an axis at right angles to that of the said concentric shafts, and geared connections located between the forks of said head for rotating one of the holding cups from the inner of the said' shafts.

4. In a polishing machine or the like, a selfcontained removable unit comprising a pair of concentric shafts journaled one within the other, a driving pinion on each shaft, a forked head on the outer of said shafts, a rotary diamond holder journaled in said head and arranged to present a diamond for cutting in the space between its forks, and geared connections between said holder and the inner of said shafts.

5. In a polishing machine or the like, a self. contained unit comprising hollow and solid shafts arranged concentrically, a head carried by the hollow shaft and rotatable therewith, a diamond holder journaled in said head to rotate about an axis at right angles to the common axis of the shafts, and worm gearing interposed between the solid shaft and said holder, whereby the latter may be driven at substantially reducedspeed through the medium of said shaft as the head is rotated.

6. A diamond polishing machine comprising a lapping wheel rotatable about a horizontal axis, a diamond holder rotatable about an axis parallel to the flat face of said wheel, means for rotating said diamond holder including inner and outer telescopically arranged shafts for supporting the holder in a position adjacent to the wheel and offset with respect to its axis, and means for driving said shafts and thereby bodily swinging the holder in a circular path in a plane located parallel to the face of the lapping wheel and located wholly at one side of the axis of said lapping wheel.

7. In a diamond polishing machine, a lapping wheel, a holder comprising a forked head, a pair of opposed cups iournaled therein and also movable endwise toward and from each other, antifriction bearings located within the forks and supporting both cups, means outside the forks for controlling the longitudinal position of the cups, inner and outer telescopically arranged shafts carrying said holder, and a driving connection with the inner of said shafts for rotating one of the cups while the head is being rotated by the outer shaft.

8. In a diamond cutting or polishing machine having a lapping wheel rotatable about a fixed axis, a removable spindle unit comprising inner and outer telescopically related shafts, a head carried by the outer of said shafts and having a pair of angular arms offset with respect to the common axis of the shafts, a wormdriven shaft journaled in said arms, a diamond holder rotatably mounted in said said arms and driven by said worm-driven shaft, and a driving worm on the inner of said telescopically y related shafts.

CHARLES DELAFONTAINE. FRANK W. KOTLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 457,866 Messaz Aug. 18, 1891 969,371 Hornigr Sept. 13, 1910 1,168,858 Coleman Jan. 18, 1916 1,373,836 Ryon Apr. 5, 1921 1,383,941 Harman July 5, 1921 1,646,375 Augenstein Oct. 18, 1927 1,702,267 Miller Feb. 19, 1929 1,913,771 Rice June 13, 1933 2,159,336 Markwick et al May 23, 1939 2,316,109 Solodar Apr. 6, 1943 2,386,687 Jearum Oct. 9, 1945 2,388,751 Levy Nov. 13, 1945 2,407,222 Boyce Sept. l0, 1946 FOREIGN PATENTS Number Country Date 377,282 Germany June 14, 1923 

